Gibson, Dunn & Crutcher LLP received $537,939 from AFER between April 1, 2012, and March 31, 2013. The organization also paid David Boies’ law firm – Boies, Schiller & Flexner LLP – $468,089 for “legal and ancillary legal expenses” between April 1, 2010, through March 31, 2011.

These expenses include payments to expert witnesses who testified against Prop 8, travel and living expenses for lawyers who lived in San Francisco for a month during a three-week trial over which now retired U.S. District Chief Judge Vaughn Walker presided in 2010. Additional costs include the use of LexisNexis and other online research databases and photo copying documents.

Prop 8 supporters raised nearly $40 million in support of the same-sex marriage ban that California voters approved in 2008.

Walker in August 2010 struck down the gay nuptials prohibition.

A three-judge panel on the 9th U.S. Circuit Court of Appeals in San Francisco in February 2012 upheld the ruling. The U.S. Supreme Court last June struck down Prop 8.

AFER’s 2013 tax filings were not available.

“AFER’s case resulted in the return of marriage equality in California for a fraction of the cost of a ballot measure,” AFER Executive Director Adam Umhoefer told the Washington Blade on Tuesday.

Tax filings also indicate AFER raised $14,900,467 between April 23, 2009, and March 31, 2013, that Umhoefer told the Blade includes a “large amount” of contributions from Republican donors. He added his organization estimates the Prop 8 case also generated millions of dollars in earned media coverage for which it did not have to pay.

“Our donors feel very strongly about return on investment,” said Umhoefer.

AFER, alongside Olson and Boies, is representing two same-sex couples – Tim Bostic and Tony London of Norfolk and Carol Schall and Mary Townley of Chesterfield – who are challenging Virginia’s constitutional amendment that defines marriage as between a man and a woman.

U.S. District Judge Arenda L. Wright Allen last month struck down the commonwealth’s gay nuptials ban that Attorney General Mark Herring in January announced he would not defend. The 4th U.S. Circuit Court of Appeals in Richmond, Va., in May is scheduled to hold oral arguments in the AFER case and a second lawsuit Lambda Legal and the American Civil Liberties Union filed last summer on behalf of Christy Berghoff and Victoria Kidd of Winchester and Joanne Harris and Jessica Duff of Staunton that has been certified as a class action.

Umhoefer told the Blade his organization’s costs in the Bostic case will be “significantly lower” than the amount of money it spent to challenge Prop 8 because the lawsuit against Virginia’s same-sex marriage ban has worked its way through the courts much faster. He said he expects the 4th U.S. Circuit Court of Appeals will issue its ruling sometime this summer – roughly a year after Bostic and London filed their lawsuit.